To conserve water at home, the best options would be:
- Washing dishes only when the dishwasher is full - This practice ensures that you are maximizing the efficiency of water use as dishwashers typically use less water than washing dishes by hand.
As for the other options:
- Rinsing dishes with cool water instead of warm water: While this may save energy, it doesn't significantly save water compared to using a full dishwasher.
- Bathing pets with a hose instead of a bucket: This can waste water, especially if the hose is left running. Using a bucket may be more water-efficient.
- Eating fish bought from the store: This doesn’t directly relate to water conservation at home.
Thus, option 2 (washing dishes only when the dishwasher is full) is the best way to conserve water at home.